20 BULLETIN 1475, IT. S. DEPARTMENT OF AGRICULTURE 
are used chiefly for technical purposes. In India and some other 
countries mustard-seed oil is used for edible purposes. 
In the United States and Europe large quantities of the oil are 
obtained as a by-product in the manufacture of mustard flour and 
prepared mustards. 
RAPESEED (COLZA) OIL 
Rapeseed oil is obtained from the seeds of several varieties of the 
rape plant growing in India. Japan, and many European countries. 
The oil content of the seed ranges from 30 to 45 per cent. 
Rapeseed oil is obtained both by expression and extraction with 
volatile solvents. It can be refined with sulphuric acid or with 
caustic soda in the same manner as linseed oil (p. 23). To increase 
its viscosity, air is frequently blown through the heated oil. 
The cold-pressed oil is used for edible purposes in India and also 
in some European countries. The hot-pressed and solvent-extracted 
oil serves various technical purposes. The chief use of the oil, both 
here and abroad, is as a lubricant, particularly after it has been 
blown (p. 23). Some is used in soap making and for quenching 
or tempering steel plates. If free from mustard seed, the press 
cake or extracted meal is used as a cattle food in Europe. Other- 
wise it is used as a fertilizer. 
CACAO BUTTER 
Theobroma cacao plants, from which chocolate, cocoa, and cacao 
butter are obtained, grow in the tropical parts of South America, 
the West Indies, Africa. India, and other regions. Cacao beans r 
as the seeds of these plants are called, contain from 50 to 57 per 
cent of oil. 
Cacao butter is usually a by-product from the manufacture of 
beverage cocoa, which is made by pressing decorticated roasted and 
crushed cacao beans. The press cake when ground and bolted con- 
stitutes cocoa; the expressed fat is cacao butter. Cacao butter can 
also be made by pressing ground unroasted beans. Some cacao 
butter is obtained by extracting the press cake or cocoa with a vola- 
tile solvent. TVTien freshly extracted, cacao butter has a pale yel- 
lowish color, which becomes white after the product has stood for 
a few days. 
Although the chief use of cacao butter is in the manufacture of 
confectionery, it is also an important ingredient of several pharma- 
ceutical preparations. 
SHEA-NUT OIL OR BUTTER 
Shea-nut oil or butter, also called bambuk butter, karite oil, and 
Galam butter, is a semisolid oil obtained from the nut of a tree 
belonging to the Sapotacese. which grows abundantly on the west 
coast of Africa in the English and French Sudan. In size and shape 
the nuts resemble an ordinary plum. The oil content of the kernels 
ranges from 40 to 55 per cent. 
In tropical Africa the natives extract the oil from the crushed 
nuts with boiling water. Comparative^ little is extracted for ex- 
port. Practically all that is used in the United States is obtained 
from imported nuts. In Africa the oil is used for edible purposes. 
That expressed in the United States goes to the soap makers. 
